Proposals to revise the Statutes of the International Committee on Systematics of Prokaryotes.

The International Committee on Systematics of Prokaryotes serves to administer the rules of prokaryotic nomenclature via the International Code of Nomenclature of Prokaryotes, ensures the publication of the International Journal of Systematic and Evolutionary Microbiology, and works to represent the interests of the microbiological disciplines regarding prokaryotic nomenclature. The functions and mechanisms of operation of the International Committee on Systematics of Prokaryotes (ICSP) are defined in its Statutes, which were last revised in 2019. As members of the 2020-2023 and the 2023-2026 ICSP Executive Board and the Judicial Commission, we propose here some further revisions to help improve the clarity and functionality of the Statutes.

Microbiome and Resistome Profiles along a Sewage-Effluent-Reservoir Trajectory Underline the Role of Natural Attenuation in Wastewater Stabilization Reservoirs.

Antibiotic-resistant bacteria and antibiotic resistance gene (ARGs) loads dissipate through sewage treatment plants to receiving aquatic environments, but the mechanisms that mitigate the spread of these ARGs are not well understood due to the complexity of full-scale systems and the difficulty of source tracking in downstream environments. To overcome this problem, we targeted a controlled experimental system comprising a semicommercial membrane-aerated bioreactor (MABR), whose effluents fed a 4,500-L polypropylene basin that mimicked effluent stabilization reservoirs and receiving aquatic ecosystems. We analyzed a large set of physicochemical measurements, concomitant with the cultivation of total and cefotaxime-resistant Escherichia coli, microbial community analyses, and quantitative PCR (qPCR)/digital droplet PCR (ddPCR) quantification of selected ARGs and mobile genetic elements (MGEs). The MABR removed most of the sewage-derived organic carbon and nitrogen, and simultaneously, E. coli, ARG, and MGE levels dropped by approximately 1.5- and 1.0-log unit mL-1, respectively. Similar levels of E. coli, ARGs, and MGEs were removed in the reservoir, but interestingly, unlike in the MABR, the relative abundance (normalized to 16S rRNA gene-inferred total bacterial abundance) of these genes also decreased. Microbial community analyses revealed the substantial shifts in bacterial and eukaryotic community composition in the reservoir relative to the MABR. Collectively, our observations lead us to conclude that the removal of ARGs in the MABR is mainly a consequence of treatment-facilitated biomass removal, whereas in the stabilization reservoir, mitigation is linked to natural attenuation associated with ecosystem functioning, which includes abiotic parameters, and the development of native microbiomes that prevent the establishment of wastewater-derived bacteria and associated ARGs. IMPORTANCE Wastewater treatment plants are sources of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), which can contaminate receiving aquatic environments and contribute to antibiotic resistance. We focused on a controlled experimental system comprising a semicommercial membrane-aerated bioreactor (MABR) that treated raw sewage, whose effluents fed a 4,500-L polypropylene basin that mimicked effluent stabilization reservoirs. We evaluated ARB and ARG dynamics across the raw-sewage-MABR-effluent trajectory, concomitant with evaluation of microbial community composition and physicochemical parameters, in an attempt to identify mechanisms associated with ARB and ARG dissipation. We found that removal of ARB and ARGs in the MABR was primarily associated with bacterial death or sludge removal, whereas in the reservoir it was attributed to the inability of ARBs and associated ARGs to colonize the reservoir due to a dynamic and persistent microbial community. The study demonstrates the importance of ecosystem functioning in removing microbial contaminants from wastewater.

Every fifth published metagenome is not available to science.

Have you ever sought to use metagenomic DNA sequences reported in scientific publications? Were you successful? Here, we reveal that metagenomes from no fewer than 20% of the papers found in our literature search, published between 2016 and 2019, were not deposited in a repository or were simply inaccessible. The proportion of inaccessible data within the literature has been increasing year-on-year. Noncompliance with Open Data is best predicted by the scientific discipline of the journal. The number of citations, journal type (e.g., Open Access or subscription journals), and publisher are not good predictors of data accessibility. However, many publications in high-impact factor journals do display a higher likelihood of accessible metagenomic data sets. Twenty-first century science demands compliance with the ethical standard of data sharing of metagenomes and DNA sequence data more broadly. Data accessibility must become one of the routine and mandatory components of manuscript submissions-a requirement that should be applicable across the increasing number of disciplines using metagenomics. Compliance must be ensured and reinforced by funders, publishers, editors, reviewers, and, ultimately, the authors.

Toward a Universal Unit for Quantification of Antibiotic Resistance Genes in Environmental Samples.

Surveillance of antibiotic resistance genes (ARGs) has been increasingly conducted in environmental sectors to complement the surveys in human and animal sectors under the "One-Health" framework. However, there are substantial challenges in comparing and synthesizing the results of multiple studies that employ different test methods and approaches in bioinformatic analysis. In this article, we consider the commonly used quantification units (ARG copy per cell, ARG copy per genome, ARG density, ARG copy per 16S rRNA gene, RPKM, coverage, PPM, etc.) for profiling ARGs and suggest a universal unit (ARG copy per cell) for reporting such biological measurements of samples and improving the comparability of different surveillance efforts.

Survival of clinical and environmental carbapenem-resistant Klebsiella pneumoniae ST147 in surface water.

Carbapenem-resistant Klebsiella pneumoniae represents a healthcare threat, already disseminated in the environment. This study aimed to compare the behaviour of a clinical and an environmental K. pneumoniae strain (multilocus sequence type ST147) harbouring the gene blaKPC-3 in water. The abundance of the genes phoE (specific for K. pneumoniae) and blaKPC-3 was monitored by quantitative PCR in urban runoff water and sterile ultra-pure water microcosms, aiming to assess survival, blaKPC-3 persistence, and the effect of the native water microbiota. In sterile ultra-pure water, the abundance of cultivable K. pneumoniae and blaKPC-3 gene did not change over the incubation period (8 days). In contrast, in urban runoff, the K. pneumoniae and the genes phoE and blaKPC genes decreased by up to 3 log-units. These results suggest that K. pneumoniae were outcompeted by the native microbiota of the urban runoff water and that the decay of blaKPC-3 gene was due to host death, rather than to gene loss. The study highlights that although native microbiota is essential to hamper the persistence of non-native bacteria, carbapenemase producing K. pneumoniae can survive in urban runoff water for at least one week.

Pseudomonadota in the oral cavity: a glimpse into the environment-human nexus.

The phylum Pseudomonadota is amongst the most represented in the environment, with a comparatively lower prevalence in the human oral cavity. The ubiquity of Pseudomonadota and the fact that the oral cavity is the most likely entry portal of bacteria from external sources underlie the need to better understand its occurrence in the interface environment-humans. Yet, the relevance oral Pseudomonadota is largely underexplored in the scientific literature, a gap that this review aims at addressing by making, for the first time, an overview of the diversity and ecology of Pseudomonadota in the oral cavity. The screening of scientific literature and human microbiome databases unveiled 1328 reports of Pseudomonadota in the oral cavity. Most of these belonged to the classes Beta- and Gammaproteobacteria, mainly to the families Neisseriaceae, Campylobacteriaceae, and Pasteurelaceae. Others also regularly reported include genera such as Enterobacter, Klebsiella, Acinetobacter, Escherichia, Burkholderia, or Citrobacter, whose members have high potential to acquire virulence and antibiotic resistance genes. This review provides evidence that clinically relevant environmental Pseudomonadota may colonize humans via oral cavity. The need for further investigation about Pseudomonadota at the environment-oral cavity interface and their role as vectors potentially involved in virulence and antibiotic resistance transmission is demonstrated. KEY POINTS: • Neisseriaceae, Campylobacteriaceae, and Pasteurelaceae are part of the core oral microbiome • Enterobacteriaceae, Acinetobacter, or Burkholderia are frequent in the oral microbiome • Gut dysbiosis may be associated with colonization by ubiquitous oral Pseudomonadota.

Dissemination of Metallo-ß-Lactamase-Producing Pseudomonas aeruginosa in Serbian Hospital Settings: Expansion of ST235 and ST654 Clones.

This nationwide study aimed to investigate the molecular characteristics of metallo-ß-lactamase (MBL)-producing Pseudomonas aeruginosa in Serbia, underlying resistance mechanisms, the genetic context of detected MBL genes, and the clonal relationship between isolates harboring genes-encoding MBL. Overall, 320/5334 isolates collected from 2018 to 2021 were identified as P. aeruginosa. Carbapenem-resistant P. aeruginosa (CRPA) were screened for the presence of blaVIM, blaIMP, and blaNDM, genes whereas MBL-positive isolates were tested for the presence of the blaCTX-M-2, blaPER, blaTEM, blaSHV, blaVEB, and blaGES. Multilocus sequence typing and phylogenomic analysis were performed for P. aeruginosa-producing MBL. The majority of the P. aeruginosa isolates were recovered from the lower respiratory tract (n = 120; 37.5%) and wound specimens (n = 108; 33.75%). CRPA isolates accounted for 43.1% (n = 138) of the tested isolates, 31 out of them being blaNDM-1-positive (22.5%). The colistin resistance rate was 0.3%. MLST analysis revealed the occurrence of ST235 (n = 25) and ST654 (n = 6), mostly confined to Serbia. The distribution of beta-lactamase-encoding genes in these isolates suggested clonal dissemination and possible recombination: ST235/blaNDM-1, ST235/blaNDM-1/blaPER-1, ST654/blaNDM-1, ST654/blaNDM-1/blaPER-1, and ST654/blaNDM-1/blaGES-5. High-risk clones ST235 and ST654 identified for the first time in Serbia, are important vectors of acquired MBL and ESBL and their associated multidrug resistance phenotypes represent a cause for considerable concern.

Third generation cephalosporin-resistant Klebsiella pneumoniae thriving in patients and in wastewater: what do they have in common?

BACKGROUND: Klebsiella pneumoniae are ubiquitous bacteria and recognized multidrug-resistant opportunistic pathogens that can be released into the environment, mainly through sewage, where they can survive even after wastewater treatment. A major question is if once released into wastewater, the selection of lineages missing clinically-relevant traits may occur. Wastewater (n = 25) and clinical (n = 34) 3rd generation cephalosporin-resistant K. pneumoniae isolates were compared based on phenotypic, genotypic and genomic analyses. RESULTS: Clinical and wastewater isolates were indistinguishable based on phenotypic and genotypic characterization. The analysis of whole genome sequences of 22 isolates showed that antibiotic and metal resistance or virulence genes, were associated with mobile genetic elements, mostly transposons, insertion sequences or integrative and conjugative elements. These features were variable among isolates, according to the respective genetic lineage rather than the origin. CONCLUSIONS: It is suggested that once acquired, clinically relevant features of K. pneumoniae may be preserved in wastewater, even after treatment. This evidence highlights the high capacity of K. pneumoniae for spreading through wastewater, enhancing the risks of transmission back to humans.

Living with sulfonamides: a diverse range of mechanisms observed in bacteria.

Sulfonamides are the oldest class of synthetic antibiotics still in use in clinical and veterinary settings. The intensive utilization of sulfonamides has been leading to the widespread contamination of the environment with these xenobiotic compounds. Consequently, in addition to pathogens and commensals, also bacteria inhabiting a wide diversity of environmental compartments have been in contact with sulfonamides for almost 90 years. This review aims at giving an overview of the effect of sulfonamides on bacterial cells, including the strategies used by bacteria to cope with these bacteriostatic agents. These include mechanisms of antibiotic resistance, co-metabolic transformation, and partial or total mineralization of sulfonamides. Possible implications of these mechanisms on the ecosystems and dissemination of antibiotic resistance are also discussed. KEY POINTS: • Sulfonamides are widespread xenobiotic pollutants; • Target alteration is the main sulfonamide resistance mechanism observed in bacteria; • Sulfonamides can be modified, degraded, or used as nutrients by some bacteria.

Betaproteobacteria are predominant in drinking water: are there reasons for concern?

Betaproteobacteria include some of the most abundant and ubiquitous bacterial genera that can be found in drinking water, including mineral water. The combination of physiology and ecology traits place some Betaproteobacteria in the list of potential, yet sometimes neglected, opportunistic pathogens that can be transmitted by water or aqueous solutions. Indeed, some drinking water Betaproteobacteria with intrinsic and sometimes acquired antibiotic resistance, harbouring virulence factors and often found in biofilm structures, can persist after water disinfection and reach the consumer. This literature review summarises and discusses the current knowledge about the occurrence and implications of Betaproteobacteria in drinking water. Although the sparse knowledge on the ecology and physiology of Betaproteobacteria thriving in tap or bottled natural mineral/spring drinking water (DW) is an evidence of this review, it is demonstrated that DW holds a high diversity of Betaproteobacteria, whose presence may not be innocuous. Frequently belonging to genera also found in humans, DW Betaproteobacteria are ubiquitous in different habitats, have the potential to resist antibiotics either due to intrinsic or acquired mechanisms, and hold different virulence factors. The combination of these factors places DW Betaproteobacteria in the list of candidates of emerging opportunistic pathogens. Improved bacterial identification of clinical isolates associated with opportunistic infections and additional genomic and physiological studies may contribute to elucidate the potential impact of these bacteria.

Oryzisolibacter propanilivorax gen. nov., sp. nov., a propanil-degrading bacterium.

Strain EPL6T, a Gram-negative, motile, short rod was isolated from a propanil and 3,4-dichloroaniline enrichment culture produced from rice paddy soil. Based on the analyses of the 16S rRNA gene sequence, strain EPL6T was observed to be a member of the family Comamonadaceae, sharing the highest pairwise identity with type strains of the species Alicycliphilus denitrificans K601T (96.8 %) and Melaminivora alkalimesophila CY1T (96.8 %). Strain EPL6T was able to grow in a temperature range of 15-37 °C, pH 6-9 and in the presence of up to 4 % (w/v) NaCl and tested positive for catalase and oxidase reactions. The major respiratory quinone was Q8. The genomic DNA had a G+C content of 69.4±0.9 mol%. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol, and the major fatty acid methyl esters comprised C16 : 0, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c/iso-C15 : 0 2-OH). Comparison of the genome sequence of strain EPL6T and of its closest neighbours, Melaminivora alkalimesophila CY1T and Alicycliphilus denitrificans K601T, yielded values of ANI ≤84.1 % and of AAI ≤80.3 %. Therefore, the genetic, phylogenetic, phenotypic and chemotaxonomic characteristics support the classification of this organism into a new taxon. Considering the genetic divergence of strain EPL6T from the type strains of the closest species, which belong to distinct genera, we propose a new genus within the family Comamonadaceae, named Oryzisolibacter propanilivorax gen. nov., sp. nov., represented by the isolate EPL6T as the type strain of the species (=LMG 28427T=CECT 8927T).

Toward a Comprehensive Strategy to Mitigate Dissemination of Environmental Sources of Antibiotic Resistance.

Antibiotic resistance is a pervasive global health threat. To combat the spread of resistance, it is necessary to consider all possible sources and understand the pathways and mechanisms by which resistance disseminates. Best management practices are urgently needed to provide barriers to the spread of resistance and maximize the lifespan of antibiotics as a precious resource. Herein we advise upon the need for coordinated national and international strategies, highlighting three essential components: (1) Monitoring, (2) Risk Assessment, and (3) Mitigation of antibiotic resistance. Central to all three components is What exactly to monitor, assess, and mitigate? We address this question within an environmental framework, drawing from fundamental microbial ecological processes driving the spread of resistance.

Characterization of bacterial communities from Masseiras, a unique Portuguese greenhouse agricultural system.

"Masseiras" is an ancient Portuguese agriculture system, where soil was developed from sand dunes enriched with seaweeds over more than a century. Due to the importance for the local economy, this system evolved for greenhouse structures. In this study we compared the bacterial community composition and structure of "Masseiras" soil, aiming at assessing the potential impact of different agricultural practices. The bulk soil of two greenhouses (following or not the recommended agriculture good practices, FGP and NFGP, respectively) was compared based on their physicochemical properties and bacterial community. In both FGP and NFGP, Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Gemmatimonadetes were in a proportion of 5:1:1:1:1:1. However, the bacterial community of soil FGP was richer and more diverse than that of soil NFGP. Members of the classes Bacilli and Gemm-1, with higher relative abundance in NFGP and FGP, respectively, were those contributing most for distinguishing the bacterial communities of both soils. The differences in the structure of the bacterial communities correlated (Mantel test) with some soil physicochemical properties, such as electrical conductivity and nitrate and Zn contents, which were significantly higher in soil NFGP than in soil FGP.

High Throughput Analysis of Integron Gene Cassettes in Wastewater Environments.

Integrons are extensively targeted as a proxy for anthropogenic impact in the environment. We developed a novel high-throughput amplicon sequencing pipeline that enables characterization of thousands of integron gene cassette-associated reads, and applied it to acquire a comprehensive overview of gene cassette composition in effluents from wastewater treatment facilities across Europe. Between 38 100 and 172 995 reads per-sample were generated and functionally characterized by screening against nr, SEED, ARDB and ß-lactamase databases. Over 75% of the reads were characterized as hypothetical, but thousands were associated with toxin-antitoxin systems, DNA repair, cell membrane function, detoxification and aminoglycoside and ß-lactam resistance. Among the reads characterized as ß-lactamases, the carbapenemase blaOXA was dominant in most of the effluents, except for Cyprus and Israel where blaGES was also abundant. Quantitative PCR assessment of blaOXA and blaGES genes in the European effluents revealed similar trends to those displayed in the integron amplicon sequencing pipeline described above, corroborating the robustness of this method and suggesting that these integron-associated genes may be excellent targets for source tracking of effluents in downstream environments. Further application of the above analyses revealed several order-of-magnitude reductions in effluent-associated ß-lactamase genes in effluent-saturated soils, suggesting marginal persistence in the soil microbiome.

Antibiotic resistance in urban aquatic environments: can it be controlled?

Over the last decade, numerous evidences have contributed to establish a link between the natural and human-impacted environments and the growing public health threat that is the antimicrobial resistance. In the environment, in particular in areas subjected to strong anthropogenic pressures, water plays a major role on the transformation and transport of contaminants including antibiotic residues, antibiotic-resistant bacteria, and antibiotic resistance genes. Therefore, the urban water cycle, comprising water abstraction, disinfection, and distribution for human consumption, and the collection, treatment, and delivery of wastewater to the environment, is a particularly interesting loop to track the fate of antibiotic resistance in the environment and to assess the risks of its transmission back to humans. In this article, the relevance of different transepts of the urban water cycle on the potential enrichment and spread of antibiotic resistance is reviewed. According to this analysis, some gaps of knowledge, research needs, and control measures are suggested. The critical rationale behind the measures suggested and the desirable involvement of some key action players is also discussed.

Bombella intestini gen. nov., sp. nov., an acetic acid bacterium isolated from bumble bee crop.

In the frame of a bumble bee gut microbiota study, acetic acid bacteria (AAB) were isolated using a combination of direct isolation methods and enrichment procedures. MALDI-TOF MS profiling of the isolates and a comparison of these profiles with profiles of established AAB species identified most isolates as Asaia astilbis or as 'Commensalibacter intestini', except for two isolates (R-52486 and LMG 28161(T)) that showed an identical profile. A nearly complete 16S rRNA gene sequence of strain LMG 28161(T) was determined and showed the highest pairwise similarity to Saccharibacter floricola S-877(T) (96.5%), which corresponded with genus level divergence in the family Acetobacteraceae. Isolate LMG 28161(T) was subjected to whole-genome shotgun sequencing; a 16S-23S rRNA internal transcribed spacer (ITS) sequence as well as partial sequences of the housekeeping genes dnaK, groEL and rpoB were extracted for phylogenetic analyses. The obtained data confirmed that this isolate is best classified into a new genus in the family Acetobacteraceae. The DNA G+C content of strain LMG 28161(T) was 54.9 mol%. The fatty acid compositions of isolates R-52486 and LMG 28161(T) were similar to those of established AAB species [with C18:1ω7c (43.1%) as the major component], but the amounts of fatty acids such as C19:0 cyclo ω8c, C14:0 and C14:0 2-OH enabled to differentiate them. The major ubiquinone was Q-10. Both isolates could also be differentiated from the known genera of AAB by means of biochemical characteristics, such as their inability to oxidize ethanol to acetic acid, negligible acid production from melibiose, and notable acid production from d-fructose, sucrose and d-mannitol. In addition, they produced 2-keto-d-gluconate, but not 5-keto-d-gluconate from d-glucose. Therefore, the name Bombella intestini gen nov., sp. nov. is proposed for this new taxon, with LMG 28161(T) ( =DSM 28636(T) =R-52487(T)) as the type strain of the type species.

Bordetella bronchialis sp. nov., Bordetella flabilis sp. nov. and Bordetella sputigena sp. nov., isolated from human respiratory specimens, and reclassification of Achromobacter sediminum Zhang et al. 2014 as Verticia sediminum gen. nov., comb. nov.

The phenotypic and genotypic characteristics of four Bordetella hinzii-like strains from human respiratory specimens and representing nrdA gene sequence based genogroups 3, 14 and 15 were examined. In a 16S rRNA gene sequence based phylogenetic tree, the four strains consistently formed a single coherent lineage but their assignment to the genus Bordetella was equivocal. The respiratory quinone, polar lipid and fatty acid profiles generally conformed to those of species of the genus Bordetella and were characterized by the presence of ubiquinone 8, of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several aminolipids, and of high percentages of C16 : 0, cyclo-C17 : 0 and summed feature 2, as major chemotaxonomic marker molecules, respectively. The DNA G+C content was about 66 mol%, which corresponded with that of the high-percentage DNA G+C content genera of the family Alcaligenaceae including the genus Bordetella. DNA­DNA hybridization experiments revealed the presence of three distinct genomospecies and thus confirmed phenotypic differences as revealed by means of extensive biochemical characterization. We therefore propose to formally classify Bordetella genogroups 3, 14 and 15 as Bordetella bronchialis sp. nov. (type strain LMG 28640T = AU3182T = CCUG 56828T), Bordetella sputigena sp. nov. (type strain LMG 28641T = CCUG 56478T) and Bordetella flabilis sp. nov. (type strain LMG 28642T = AU10664T = CCUG 56827T). In addition, we propose to reclassify Achromobacter sediminum into the novel genus Verticia, as Verticia sediminum, gen. nov., comb. nov., on the basis of its unique phylogenetic position, its marine origin and its distinctive phenotypic, fatty acid and polar lipid profile.

Hydromonas duriensis gen. nov., sp. nov., isolated from freshwater.

An aerobic, Gram-stain-negative rod, designated strain A2P5T, was isolated from the Douro river, in Porto, Portugal. Cells were catalase- and oxidase-positive. Growth occurred at 15-30 °C, at pH 6-8 and in the presence of 1 % (w/v) NaCl. The major respiratory quinone was Q8, the genomic DNA had a G+C content of 47 ± 1 mol%, and phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol were amongst the major polar lipids. On the basis of 16S rRNA gene sequence analysis, strain A2P5T was observed to be a member of the family Burkholderiaceae, but could not be identified as a member of any validly named genus. The low levels of 16S rRNA gene sequence similarity to other recognized taxa ( < 91 %), together with the comparative analysis of phenotypic and chemotaxonomic characteristics, supported the proposal of a novel species of a new genus within the family Burkholderiaceae. The name Hydromonas duriensis gen. nov., sp. nov. is proposed. The type strain of Hydromonas duriensis is A2P5T ( = LMG 28428T = CCUG 66137T).

Quinolone-resistant Escherichia coli isolated from birds of prey in Portugal are genetically distinct from those isolated from water environments and gulls in Portugal, Spain and Sweden.

The influence of geographic distribution and type of habitat on the molecular epidemiology of ciprofloxacin resistant Escherichia coli was investigated. Ciprofloxacin resistant E. coli from wastewater, urban water with faecal contamination and faeces of gulls, pigeons and birds of prey, from Portugal, Spain and Sweden were compared based on multi-locus sequence typing (MLST) and quinolone resistance genetic determinants. Multi-locus sequence typing allowed the differentiation of E. coli lineages associated with birds of prey from those inhabiting gulls and waters. E. coli lineages of clinical relevance, such as the complex ST131, were detected in wastewater, streams and gulls in Portugal, Spain and Sweden. Quinolone resistance was due to gyrA and parC mutations, although distinct mutations were detected in birds of prey and in wastewater, streams and gulls isolates. These differences were correlated with specific MLST lineages, suggesting resistance inheritance. Among the plasmid-mediated quinolone resistance genes, only aac(6')-ib-cr and qnrS were detected in wastewater, streams and gulls isolates, but not in birds of prey. The horizontal transfer of the gene aac(6')-ib-cr could be inferred from its occurrence in different MLST lineages.